Assessment of Alaska reindeer populations and range conditions

Populations of reindeer (Rangifer tarandus) have fluctated greatly since their introduction to Alaska in 1891. In the 1930s, reported numbers exceeded 600 000. Presently, 38 000 reindeer graze 6.2 million ha of rangeland and woodland in Western Alaska (from 66°54'N to 52°07'N latitude). Condition of winter range producing fruticose lichens (Cladina rangiferina, Cladina arbuscula, Cladina stellaris, Cetraria cucullata, Cetraria islandica) is of major concern. Monitoring programs have been established for vegetation, fire, reindeer and wildlife. Reindeer have overgrazed lichen resources on some Bering Sea Islands. Wildfires have had the greatest impact on lichen range depletion on the mainland. Overgrazing has been a problem in localized areas. Moose (Alces alces) and muskox (Ovibos moschatus) rarely contribute to major lichen depletion. 60-80% of the mainland and 5-30% of most island winter lichen ranges are presently estimated to be in good to excellent ecological condition. Procedures for assessing condition of the lichen ranges are being further refined

Black hole radiation with high frequency dispersion

We consider one model of a black hole radiation, in which the equation of motion of a matter field is modified to cut off high frequency modes. The spectrum in the model has already been analytically derived in low frequency range, which has resulted in the Planckian distributin of the Hawking temperature. On the other hand, it has been numerically shown that its spectrum deviates from the thermal one in high frequency range. In this paper, we analytically derive the form of the deviation in the high frequency range. Our result can qualitatively explain the nature of the numerically calculated spectrum. The origin of the deviation is clarified by a simple discussion.Comment: 9 pages, 10 figures, submitted to Phys.Rev.

Volume 2 - Literature review of adsorption on metal surfaces Final report, 1 May 1966 - 2 Jul. 1967

Atom and ion desorption energy, chemisorption theory and surface bonds, work functions and potential energy in literature review of adsorption on metal surface

Magnetic moment non-conservation in magnetohydrodynamic turbulence models

The fundamental assumptions of the adiabatic theory do not apply in presence of sharp field gradients as well as in presence of well developed magnetohydrodynamic turbulence. For this reason in such conditions the magnetic moment $\mu$ is no longer expected to be constant. This can influence particle acceleration and have considerable implications in many astrophysical problems. Starting with the resonant interaction between ions and a single parallel propagating electromagnetic wave, we derive expressions for the magnetic moment trapping width $\Delta \mu$ (defined as the half peak-to-peak difference in the particle magnetic moment) and the bounce frequency $\omega_b$. We perform test-particle simulations to investigate magnetic moment behavior when resonances overlapping occurs and during the interaction of a ring-beam particle distribution with a broad-band slab spectrum. We find that magnetic moment dynamics is strictly related to pitch angle $\alpha$ for a low level of magnetic fluctuation, $\delta B/B_0 = (10^{-3}, \, 10^{-2})$, where $B_0$ is the constant and uniform background magnetic field. Stochasticity arises for intermediate fluctuation values and its effect on pitch angle is the isotropization of the distribution function $f(\alpha)$. This is a transient regime during which magnetic moment distribution $f(\mu)$ exhibits a characteristic one-sided long tail and starts to be influenced by the onset of spatial parallel diffusion, i.e., the variance $$ grows linearly in time as in normal diffusion. With strong fluctuations $f(\alpha)$ isotropizes completely, spatial diffusion sets in and $f(\mu)$ behavior is closely related to the sampling of the varying magnetic field associated with that spatial diffusion.Comment: 13 pages, 10 figures, submitted to PR

Environmental quality objective of principles and standards for planning, The

August 1975.Submitted to the Water Resources Planning Fellowship Steering Committee, Colorado State University, in fulfillment of requirements for NR 795 Special Study in Planning.Includes bibliographical references (pages 62-63)

High-Grade Prostate Cancer: Favorable Results in the Modern Era Regardless of Initial Treatment

Purpose. We performed a retrospective study to determine the outcome of a modern cohort of patients with high-grade (Gleason score ≥ 8) prostate cancer treated with radical prostatectomy, radiation therapy, or hormone therapy. Methods. We identified 404 patients in the South Texas Veteran's Healthcare System Tumor Registry diagnosed with high grade prostate cancer between 1998 and 2008. Mean follow-up was 4.62 ± 2.61 years. End points were biochemical failure-free survival, overall survival, metastasis-free survival, and cancer-specific survival. Results. 5-year overall survival for patients undergoing radical prostatectomy, radiation therapy, and hormone therapy was 88.9%, 76.3%, and 58.9%, respectively. 5-year metastasis-free survival for patients undergoing radical prostatectomy, radiation therapy, and hormone therapy was 96.8%, 96.6%, and 88.4%, respectively, and 5-year cancer-specific survival was 97.2%, 100%, and 89.9%, respectively. Patients with a Gleason score of 10 and pretreatment prostate-specific antigen > 20 ng/mL had decreased 5-year biochemical failure-free and cancer-specific survival. Patients with a pretreatment prostate-specific antigen > 20 ng/mL had decreased 5-year overall survival. Discussion. Even for patients with high-grade disease, the outcome is not as dire in the modern era regardless of primary treatment modality chosen. While there is room for improvement, we should not have a nihilistic impression of how these patients will respond to treatment

Individual differences in the shape of the nasal visual field

AbstractBetween-subject differences in the shape of the nasal visual field were assessed for 103 volunteers 21–85years of age and free of visual disorder. Perimetry was conducted with a stimulus for which contrast sensitivity is minimally affected by peripheral defocus and decreased retinal illumination. One eye each was tested for 103 volunteers free of eye disease in a multi-center prospective longitudinal study. A peripheral deviation index was computed as the difference in log contrast sensitivity at outer (25–29° nasal) and inner (8° from fixation) locations. Values for this index ranged from 0.01 (outer sensitivity slightly greater than inner sensitivity) to −0.7 log unit (outer sensitivity much lower than inner sensitivity). Mean sensitivity for the inner locations was independent of the deviation index (R2<1%), while mean sensitivity for the outer locations was not (R2=38%, p<0.0005). Age was only modestly related to the index, with a decline by 0.017 log unit per decade (R2=10%). Test-retest data for 21 volunteers who completed 7–10 visits yielded standard deviations for the index from 0.04 to 0.17 log unit, with a mean of 0.09 log unit. Between-subject differences in peripheral deviation persisted over two years of longitudinal testing. Peripheral deviation indices were correlated with indices for three other perimetric stimuli used in a subset of 24 volunteers (R2 from 20% to 49%). Between-subject variability in shape of the visual field raises concerns about current clinical visual field indices, and further studies are needed to develop improved indices